JsJacMessage GetNode

Hi, 

In JsjacMessage the node values is not possible to get from the client, this is a example.

Generate new node
```javascript
    var customValues = {
        one:1,
        two:2
    }

    var oMsg = new JSJaCMessage();
    oMsg.buildNode("newNode");
    oMsg.appendNode("newNode",customValues);
    oMsg.setTo(new JSJaCJID(sendmessage));
    oMsg.setBody(sendtext);
    con.send(oMsg);
```

This is the xml:
```xml
<message xmlns='jabber:client' to='test@192.168.100.68' from='eloy@192.168.100.68/17579aa1-0e71-4ca6-87e2-b6252d1cb3fb'><newNode one='1' two='2'/><body>hello</body></message></body>
```

In the other side of the customer, you only need use this to get all attributes:


```javascript
function handleMessage(oJSJaCPacket) {
    var attrs = oJSJaCPacket.getNodeVal("newNode");
    ... 
}
```

Cheers